ABSTRACT
A population of transformers had three observed failures over a total of 750 transformer-years in service. What is the failure rate within a 95% confidence limit?
α 0.95 2T 2 750 years 1500 years 2f 2 3 failures 6
From Table 8.7,
From Eq. (8.12.2),
λ 12.592 1500
0.0084 failures per transformer year
Based on a 95% confidence limit, the true value of λ will not exceed 0.0084 failures per transformer year.
